1. Field of the Invention
The present invention relates to a temporary connection device for a universal joint, and in particular, to a clip for preventing separation of a yoke from a shaft in temporary retention.
2. Related Background Art
A steering shaft in a steering device of a motor vehicle is extended from the inside of the vehicle toward the front part of the body thereof. However, it is difficult to install this steering shaft straight for the reason of installing technique. Accordingly, it is usually practiced to divide such steering shaft into plural parts and arrange these plural parts with angles to be connected to each other with a universal joint.
When the steering shaft is connected to the universal joint, it is necessary to insert one end of the steering shaft into a yoke of the universal joint along the axial direction thereof. However, when the shaft has been already installed on the car body for the reason of assembling, it is difficult to slide the shaft In the axial direction. Then, a temporary connection device for connecting the yoke of the universal joint and the shaft in such case has been already proposed.
FIG. 40 is a view for showing an arrangement of connection between the yoke and the shaft according to an art which is disclosed in the U.S. Pat. No. 4,900,178 as the prior art.
Referring to FIG. 40, a yoke (shank) 11 takes a substantially U shape and has tabs 11a, l1b which are extended in parallel. The tabs 11a, 11b are respectively provided with bolt bores 11c, 11d. It should be noted that the yoke 11 is rotatable around the axis X.
The yoke 11 and the shaft 12 are shown as being separated from each other in FIG. 40. However, the shaft 12 is already fixed, and the position of the yoke 11 is also fixed, so that when the shaft 12 is to be inserted into the yoke 11, it is difficult to relatively move the yoke 11 with respect to the shaft 12 in the axial direction.
Accordingly, if the yoke 11 is moved from the state shown in the drawing and rotated around the axis X, mounted on a necessary position as being lifted upward, and then pulled down toward the shaft 12, mutual engagement between the yoke 11 and the shaft 12 becomes possible without relative movement of the yoke 11 and the shaft 12 in the axial direction. After that, a bolt 13 is threadably engaged with a nut 14 and fastened up, whereby the installation of the yoke 11 and the shaft 12 is completed.
Since the lower end of the steering shaft which is to be connected to a shaft. coupling is disposed in an area of an extremely poor accessibility, such as a lower part of the vehicle, it is desired to enhance the accessibility of the connection between the shaft coupling and the steering shaft. However, unless the yoke 11 is disposed at a predetermined position (the inmost part) with respect to the shaft 12, it is impossible to insert the bolt 13 thereto.
In order to avoid such problems, such arrangement as to be described was proposed in the Japanese Patent Application Lald-Open No. 2-35222. FIGS. 41 and 42 are cross-sectional views of the yoke 11 shown in FIG. 40, cut away along a direction perpendicular to the axis of the shaft 12. In these drawings, a clip 15 is mounted on the yoke 11, and the clip 15 presses the outer end surface of a special-form nut 14 with the elasticity thereof. The special-form nut 14 has a slant surface 14a at the inner end thereof.
As shown in FIG. 41, though not engaged with the bolt 13 in a normal state, the special-form nut 14 is pressed by the clip 15 so that the inner end thereof is protruded into the yoke 11. In this case, when the yoke 11 is moved toward the shaft 12, the special-form nut 14 is moved in a direction to press back the clip 15 by the action of the slant surface 14a, as shown in FIG. 41, whereby the shaft 12 is allowed to reach the inmost part of the yoke 11. Once the shaft 12 reaches the inmost part of the yoke 11, the special-form nut 14 returns to its original position, thereby preventing the shaft 12 from falling off from the yoke 11.
FIG. 43 is a view for showing an arrangement of the prior art which is disclosed in the US Patent No. 5,358,350 and similar to that of FIGS. 41 and 42. Referring to FIG. 43, a clip 25 is disposed around a yoke 25 and is provided with a tongue 25a which is protruding in an inwardly inclined manner.
Also according to the prior art shown in FIG. 43, when the yoke 21 is moved toward a shaft 22, the tongue 25a is elastically deformed to move outward, whereby the shaft 22 is allowed to reach the inmost part of the yoke 21. Once the shaft 22 reaches the inmost part of the yoke 21, the tongue 25a returns to its original position, thereby preventing the shaft 22 from falling off from the yoke 21.
The prior art shown in FIGS. 41 and 42 has problems as to be described. Since the special-form nut 14 has a special form as mentioned above, a generally-used nut can not be used as this nut 14. As a result, the manufacturing cost will be increased.
In the case of the prior art shown in FIG. 43, when the tongue 25a returns to its original position after the shaft 22 and the yoke 21 are once assembled, it is difficult to retract the tongue 25a outwardly and separate the yoke 21 from the shaft 22 for the second time. Further, since the clip 25 is wound up to the inner part of the yoke 21 to have the tongue 25a at the tip end thereof, it is necessary to set a gap between the tabs of the yoke 21 to be larger than the shaft 22 at least by the thickness of the clip 25. However, if the gap is set large, a comparatively large space is generated between the yoke 21 and the shaft 22. In this case, it is feared that the fastening power becomes unsatisfactory if the bolt and the nut for fastening (not shown) are fastened up with the same torque, compared with a case in which this space is small.